BOSS: The Universe's Most Precise Measurement 128
Cazekiel writes "Observing the primordial sound waves created 30,000 years after the Big Bang, physicists on the Baryon Oscillation Spectroscopic Survey have determined our universe's most precise measurements: 13.5 billion years old. The article detailing the study reports: '"We've made precision measurements of the large-scale structure of the universe five to seven billion years ago — the best measure yet of the size of anything outside the Milky Way," says David Schlegel of the Physics Division at the U.S. Department of Energy's Lawrence Berkeley National Laboratory, BOSS's principal investigator. "We're pushing out to the distances when dark energy turned on, where we can start to do experiments to find out what's causing accelerating expansion."'"
Well (Score:1, Funny)
...like a boss.
Setting a new standard. (Score:2)
The scale of this survey is really quite incredible. It will serve as a benchmark for other accomplishments for years to come.
For example, I just made a remarkably roundabout pop culture joke...
Re: (Score:1)
And using these new measurements, we can determine *exactly* how roundabout it is!
Re: (Score:2)
Scientists: The universe's most productive pun machine.
Born in the Big Bang (Score:3)
Unknown lamer: please re-read article (Score:4, Informative)
Re:Unknown lamer: please re-read article (Score:5, Funny)
The Universe may be 13.75 billion years old, but it doesn't look a day over 13.5 billion. I wonder if it's had work done. Maybe some cosmic surgery to reduce those time-space stretch marks.
According to my own calculation ... (Score:2)
It says the universe is precisely 13.75 billion years old, not 13.5 billion years old.
... the universe is actually 13.74892103652974083 billion years old, and counting ...
Re: (Score:2)
I imagine there is a cloud of interstellar gas sonewhere which displays the current capacity of the universe like one of those online data storage companies.
Re: (Score:2)
I imagine there is a cloud of interstellar gas sonewhere which displays the current capacity of the universe like one of those online data storage companies.
yes, it's online data storage in the cloud... /me ducks in shame
Re: (Score:2, Insightful)
Re: (Score:3)
It says the universe is precisely 13.75 billion years old, not 13.5 billion years old.
Actually, you're both wrong. What you read is a link to a different, unrelated article that's 2 years and 2 months old [discovery.com]. I looked at the articles and papers [sdss3.org], and I don't think any claim about the age of the universe is ever made.
I think this is instead the most accurate measurement of the distance between here and very far away galaxies, and of the distances between those galaxies. But I may be wrong on that. RTFA
questionable units (Score:1)
I always try to get my head around the meaning of measuring something in units which didn't exist then.
Re: (Score:2)
Why? Would you also say it's questionable to measure the pyramids of Egypt in meters?
Re: (Score:1)
No, that's different. The meter and the pyramids do exist simultaneously.
Re: (Score:2)
The universe existed before the unit of time 'years' existed.
The universe and years exist now.
The pyramids existed before the unit of time 'meters' existed.
The pyramids and meters exist not.
Re: (Score:2)
huh? so I guess the pyramids that are still around are fake? you been watching too much "despicable me" lately?
Re: (Score:2)
Re: (Score:2)
my apologies - makes sense now. I was a bit on the attack that day lol :)
Re: (Score:2)
The logical way to measure the pyramids is in toilet paper wrapped Smoots.
Re: (Score:2)
If you mean to say that the sun and the earth didn't exist back then and that hence the "year" didn't exist, then that's nonsense. A "year" is a somewhat well defined length of time, which applies just as much now as it did then, regardless of when that length of time was first defined or when the ingredients for defining it came into existence.
Now, if you'd be talking about whether the length of time we define as a "year" nowadays is the same now as it was back then, and whether time is a universal constan
Re: (Score:3)
A year with him is like a day... :)
Re: (Score:1)
Re: (Score:1)
So? (Score:2)
Re: (Score:2)
If a mod point falls in the forrest, does anyone get karma?
Another "It answers everything" report... (Score:2, Interesting)
While this project may yield a lot of data it still won't be able to answer most of the fundamental questions. I know they have to advertise that way in order to receive sponsorship and grants, but dang it I'm tired of hearing it.
We still won't have a clue about what Dark matter is, or even if it exists. It's still a hypothesis that makes big bang models work and gives us the idea that we understand gravity.
We still won't know what the Universe was just before the big bang, or what caused it.
Cool, but I'l
Re: (Score:2)
Re:Another "It answers everything" report... (Score:4, Interesting)
Personally, I like to view the expansion of the universe as simply a reduction in the Planck length/time relative to C. This would create the perception of a force pushing everything apart (light taking increasingly long, in terms of Planck units, to travel from one point to another). Ultimately, it's just a different perspective on the same thing, but I like it because it doesn't require the conception of some sort of mysterious "dark energy" -- just an explanation of why the Planck length would slowly shift.
And I find that, too, rather simple to envision, in a number of ways. For example, one that I've been thinking about recently is that if you view the universe in terms of information processing, the distance-limited interactions like the strong force decline in frequency as the universe ages. So if there's a fixed "processing power" of the whole universe but a decreasing number of "calculations" per "unit" time, then the number of steps per "unit" time increases, which could be expressed in any number of ways toward the universe's physical constants.
Re: (Score:2, Interesting)
Re: (Score:2)
Not really, because the coulomb constant in the numerator of the fine structure constant is relative to the length of a meter, which would obviously be likewise shifting if the Planck length is shifting. What you'd find is that everything would constantly -- albeit incredilbly slowly -- be moving into a higher energy state due to the "greater distances" between objects, which would then be radiated back down. So there would be a signature, but it'd be an incredibly weak one, and one that should be expecte
Re: (Score:1)
Re: (Score:2)
I find the concept of a shifting concept much easier to picture than some unexplained force pushing everything apart over cosmological distances (very different from all known forces). The analogy would be that we're all points in a balloon and are slowly "shrinking" down into ourselves. We see each other point as being pushed apart, and our "universe" (the balloon from each other.) being driven outward at an increasing expansion rate, while really it's just us that are shrinking away from each other.
Re: (Score:2)
Dark Energy is the repulsive force that they speculate is causing us to drift apart
While technically true, that's kind of a wag the dog view of the universe. We observe that all the other galaxys are not only flying away from us, they are getting faster. According to our current understanding of nature this acceleration must be caused by some kind of force and this force must be "fed" by some kind of energy. We call this energy "dark energy". It's not a speculation that dark energy causes the acceleration, it is the definition of the phrase "dark energy".
Dark Matter is about 100% certain, but Dark Energy is closer still to a hypothesis.
The situations for dark matter and
Re: (Score:2)
I'm not a physicist, but from what I understand, it's still an open question whether Dark Matter "exists." At least according to Wikipedia, one prominent explanation is that it points to a flaw/correction needed in the current model of gravity. Whether that's additional relativity corrections over large scales, or some sort of quantum effects is still an open question.
Re: (Score:2)
In other news, the Universe still doesn't owe you an accounting of itself. Ric has more at 11.
Re: (Score:2, Informative)
No it doesn't because if you work with standard cosmology -- and if you've an alternative, please present it at a level of rigour that means people could actually work with it -- that's already ruled out. The universe is constrained to have 5% of the critical density in baryons, otherwise we get entirely the wrong abundances of heavier elements out of the models. So we've got 5% of the critical density in baryons. Excellent, that fazes no-one, we just have a very light, open universe, right? No, to get the
Re: (Score:2)
Wait, you're complaining that this project is overhyped because it doesn't claim it will answer questions like what is dark matter or what happened before the big bang?
Re: (Score:2, Funny)
Obviously it's saying that no-one in the entire universe has ever measured anything to more than three significant figures.
Title backwards and such (Score:3)
The title meant to say "BOSS: The Most Precise Measurement of the Universe". The other way round can mean these measurements are the most precise ever, which isn't even remotely true. For instance, the article says, "BOSS gives that distance to within 1.7 percent", whereas (to pick something out of a hat) the fine-structure constant has been measured to a precision of less than one part in a billion or within less than 0.0000001%.
Maybe a physicist can chime in here--how is the red shift actually measured in an experiment like this? You could of course measure the wavelength of incoming light, but how do you know what the wavelength "should" be? Are there some common spectral lines one can look for?
Also, is there any practical use to this experiment? I'm fine with pure research, but I was curious if maybe some of the techniques find application elsewhere. The article didn't mention any.
Re: (Score:2)
Even discounting the title, I can't parse the first sentence of the summary in any way that makes sense. I suspect that the summary was trying to say that they've precisely measured the age of the universe as 13.5 billion years (which isn't even right, according to the linked article).
Maybe Unknown Lamer is CmdrTaco coming back in disguise!
Re: (Score:2)
Yeah, it's a lame sentence. I forgot to criticize it in my haste to read the article and figure out what it might mean. I'm pretty sure the submitter just misunderstood the Discovery article. It uses the phrase "most precise measurements ever made" in the first paragraph and has a link to "ANALYSIS: The Universe is Precisely 13.75 Billion Years Old". Both say "precise", and a careless person might shove them together with a badly written sentence and a typo (13.5 instead of 13.75) to get the last half of th
Re: (Score:1)
it's einstein's relativity 101. no event "appears" simultaneous to two observers moving at different speeds.
there fixed that up for you...
That would be like saying 'since I cant see it it didnt happen'...
Re: (Score:3, Informative)
No it isn't, you're making a common mistake that people who pretend they know about physics make. Put it this way: leave the physics to the people who know anything about it and go back to masturbating over furry porn.
Cosmology is based on the Robertson-Walker metric. The Robertson-Walker metric contains an unambiguous time coordinate. Put an observer in that metric and, yes, they will observe a different time -- but if they're not to violate the symmetries of the metric, the differences will be at a pertur
you mad bro? (Score:2)
with the universe full of 'dark matter', how do any of us know that our bits havent been dallying with black holes?
how do you know? (Score:2)
there could be black holes in the dark matter. that's the whole point - we don't know whats in it?
Re: (Score:1)
Re:there's no such thing as a simultenaity (Score:5, Insightful)
I'm sure that people who have studied cosmology, both theoretical and observational, in extreme depth, for a period of upwards of 20 years, are going to be devestated that "Proudrooster" and "decora" on Slashdot have shattered their entire field with a few brief sentences. Such a waste of man-hours! I'm sure the two of you will be quick to provide us with alternative models of cosmology and interpret them properly for the layman, causing no ambiguities in those who don't fully comprehend the fruits of your genius.
Seriously, "a headline grab"? This is the ninth data release of a massive project that's been going for more than twenty years since it was first planned in detail, it's been studied by hundreds of extremely well qualified physicists, astronomers and engineers, and is providing data for all of us in the field to use to test models which we construct, from which we extract observable parameters, and test against observation... and you think it's a fucking headline grab? You think it's arrogant? The mind fucking boggles.
Re: (Score:1)
Re: (Score:2)
Ok.. I just updated Wikipedia. The Universe is now 13.5 billion years, it was at 13.7.
Hah, that's extra funny considering the summary's 13.5 billion number came from misquoting the Discovery article's link to an older article (by another group even) titled The Universe is Precisely 13.75 Billion Years Old [discovery.com]. You and the submitter might hit it off nicely--you'd at least be able to talk about your remarkable lack of attention to detail.
I'm pretty sure you're joking about editing Wikipedia, but really you have no idea what you're talking about. Being confused by time dilation is for undergraduate
Re: (Score:2)
You make it sound like it would be a noteworthy feat if someone attempted the task and had some measure of success.
Re: (Score:2)
Re: (Score:2)
it's einstein's relativity 101. no event appears "simultaneous" to two observers moving at different speeds.
Ok, but we are discussing 10^87 observers that are all moving at the same speed (C)
therefore there is no such thing as the 'beginning of the universe' common to all reference frames.
Therefore if you start with proven incorrect assumptions, you will only get proven incorrect answers.
how do you know all those observers (Score:2)
are moving at c? that seems like a big assumption to me.
Re: (Score:2)
how do you know all those observers ... are moving at c? that seems like a big assumption to me.
That's the only speed photons CAN move at. At least according to the Relativity 101 quoted by the parent poster...
Primordial sound waves? (Score:3)
Thought this was going to be about a Stones concert tour.
Never mind.
Re: (Score:3)
Nosferatu? (Score:2)
Re: (Score:2)
Thought this was going to be about a *Springsteen* concert tour.
TFTFY. The headline was "BOSS" :P
Years? (Score:2)
Re: (Score:2)
I was thinking the same thing. If you ask that sort of question, isn't it incumbent upon you to explain what terms we should be using instead, and also preferably why? Otherwise, you're just trolling.
Re: (Score:2)
Why do we use years as time measurement for events that happen in the universe? Years are an Earth measurement that have no bearing on anything else in the universe.
For the same reason you asked that question in English instead of a dialect from Flartibartfast IV.
Worst (Score:1)
Worst summary ever.
Re: (Score:2)
Worst summary ever.
Welcome to slashdot. I hope you stay a while.
more detailed info (Score:2)
The press releases linked to from the /. summary are pretty thin. The Wikipedia article [wikipedia.org]
is a lot better. Here are the two papers: [1] [arxiv.org], [2] [arxiv.org].
What's causing accelerated expansion? (Score:2, Interesting)
It's pretty obvious, just people aren't thinking about it from the right mindset:
It has to do with the expansion of outer shell of the edge the remnants of the original big bang explosion; It's really a type of a 'less resistance' problem, like as if something like air resistance gets less as the perimeter of the expanding explosion moves out, yet the mass of the universe remains the same. [Although that explanation ignores the fact that there's not a whole lot of air in space, but bear with me.]
Although it
Re: (Score:2)
I see I didn't make myself clear enough, and was being distracted while I wrote that.
The point I was trying to make was simply the fact that the universe is expanding constantly, but the amount of the mass in the universe stays the same. I spent too much time on creating the balloon analogy and not enough on the the thing I was trying to focus on: everything's moving outwards from a center point; the mass remains the same yet the volume continues to increase. (Nothing to do with a secondary collision in the
Re: (Score:2)
No, although with my bungled explanation of the balloon analogy I can see why you thought that. :)
There's apparently nothing outside the edge of the universe, so while it's not 'sucking the universe bigger', it's also not resisting:
All particles trying to reach an equilibrium as the average density of the universe constantly lessening (increasing universal volume, yet a static amount of mass.) seem to have something to do with the acceleration.
I have a hole in my understanding of why particles seek an equil
Re: (Score:2)
In the beginning, there was nothing, which exploded... :)
(Who said that? Douglas Adams?)
I find it hard to care (Score:2)
About something that was 8 orders of magnitude longer in the past than my own life expectancy. Well, I do not begrudge these people their intellectual exercise, I just hope they did not spend a lot of money on this irrelevant result.
Old news (Score:2)
"We've made precision measurements of the large-scale structure of the universe five to seven billion years ago"...
And they're just now getting around to telling us about it?
Precision Measurements (Score:1)
The primordial sound was ....? (Score:2)